I had severe scoliosis (curvature of the spine) when I was younger and going to the chiropractor was what was needed to cure it and it did cure it...I'm totally "straight spined" now....so when needed, I love 'em.
I went to the chiropractor a few times after I dislocated my shoulder. I had a lot of back issues from the incident, and my regular doctor suggested the chiropractor. It did help a little bit, but I still have back issues that were never resolved.
My friend's a medical doctor and I asked her about it once. She said she would never be for it because if the practitioner makes one mistake, there goes your back. I thought about it and realized it's not worth the risk for me.